title: Occurrence of leptospirosis among suspected cases in Chennai, Tamil Nadu.
abstract: OBJECTIVE
  To evaluate the serological profile of leptospirosis by microscopic agglutination test (MAT) and dark field microscopy (DFM) and to determine the serovar prevalence rate among patients with pyrexia of unknown origin.
  
  
  METHODS
  A total of 3830 blood samples were received from different hospitals and laboratories in and around Chennai. They were screened for leptospirosis by MAT and direct observation of live Leptospira by DFM.
  
  
  RESULTS
  A total of 748 (19.5%) Leptospira positive cases were identified; among these, 36.76% were Leptospira australis, 30% were Leptospira canicola, 14.57% were Leptospira autumnalis, 12% were Leptospira icterohaemorrhagiae, 4.68% were Leptospira patoc and 1.87% were Leptospira grippotyposa. Patients were in the age group of 1-86 years, with a median age of 43.5 years. 50% positive cases were in the age group of 10-35 years. Majority of the Leptospira infected cases were males (62.98%) than females (37.02%).
  
  
  CONCLUSIONS
  Leptospirosis occurs in Chennai throughout the year although the number and positivity of cases increased during the monsoon season.
authors.affiliation: Department of Experimental Medicine, TN Dr. MGR Medical University, Chennai, Guindy, Tamil Nadu, India.
authors.forename: Ganesan
authors.initials: G
authors.lastname: Arumugam
authors.forename: S Mini
authors.initials: SM
authors.lastname: Jacob
authors.forename: D
authors.initials: D
authors.lastname: Anitha
authors.forename: Sivakumar Mampakkam
authors.initials: SM
authors.lastname: Rajappa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000372:Agglutination Tests; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D007919:Leptospira / Q000302:isolation & purification*; D007922:Leptospirosis / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D015995:Prevalence; D055815:Young Adult